Objective-C

Call a JavaScript Function Returning an Array

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Demonstrates how to call a JavaScript function that returns an array. Objective-C

#import <CkoStringBuilder.h>
#import <CkoJs.h>
#import <CkoJsonObject.h>

BOOL success = NO;

// ----------------------------------------------------------------------------------
// The Javascript functions called in this example are shown at the bottom of this page.
// -----------------------------------------------------------------------------------

CkoStringBuilder *sbScript = [[CkoStringBuilder alloc] init];
success = [sbScript LoadFile: @"js_function_returning_array.js" charset: @"utf-8"];
if (success == NO) {
    NSLog(@"%@",sbScript.LastErrorText);
    return;
}

CkoJs *js = [[CkoJs alloc] init];

CkoJsonObject *result = [[CkoJsonObject alloc] init];
result.EmitCompact = NO;

// Call Eval to add the function to the context's global object
success = [js Eval: sbScript result: result];
if (success == NO) {
    // Examine the result for an exception.
    NSLog(@"%@",[result Emit]);

    // Also examine the LastErrorText.
    NSLog(@"%@",js.LastErrorText);
    return;
}

// ------------------------------------------------------------------------------
// Call each function

CkoJsonObject *funcCall = [[CkoJsonObject alloc] init];

// Create JSON specifying the function name and arguments
// The function has no arguments, so we only specify the name.

[funcCall UpdateString: @"name" value: @"getDays"];

success = [js CallFunction: funcCall result: result];
if (success == NO) {
    // Examine the result for an exception.
    NSLog(@"%@",[result Emit]);

    // Also examine the LastErrorText.
    NSLog(@"%@",js.LastErrorText);
    return;
}

NSLog(@"%@",[result Emit]);

// Output:
// {
//   "type": "array",
//   "value": [
//     "Monday",
//     "Tuesday",
//     "Wednesday",
//     "Thursday",
//     "Friday"
//   ]
// }

// Access each array value..
int count = [[result SizeOfArray: @"value"] intValue];
int i = 0;
while (i < count) {
    result.I = [NSNumber numberWithInt: i];
    NSLog(@"%@",[result StringOf: @"value[i]"]);
    i = i + 1;
}

// ------------------------------------------------------------------------------
// Call the getRange(start,end) function

[funcCall Clear];
[funcCall UpdateString: @"name" value: @"getRange"];
[funcCall UpdateInt: @"args[0]" value: [NSNumber numberWithInt: 14]];
[funcCall UpdateInt: @"args[1]" value: [NSNumber numberWithInt: 21]];
success = [js CallFunction: funcCall result: result];
NSLog(@"%@",[result Emit]);

// Output:
// {
//   "type": "array",
//   "value": [
//     14,
//     15,
//     16,
//     17,
//     18,
//     19,
//     20,
//     21
//   ]
// }

count = [[result SizeOfArray: @"value"] intValue];
i = 0;
while (i < count) {
    result.I = [NSNumber numberWithInt: i];
    NSLog(@"%d",[[result IntOf: @"value[i]"] intValue]);
    i = i + 1;
}

// ------------------------------------------------------------------------------
// Call the getEmployees() function

[funcCall Clear];
[funcCall UpdateString: @"name" value: @"getEmployees"];
success = [js CallFunction: funcCall result: result];
NSLog(@"%@",[result Emit]);

// Output:
// {
//   "type": "array",
//   "value": [
//     {
//       "id": 101,
//       "name": "Alice",
//       "role": "Dev"
//     },
//     {
//       "id": 102,
//       "name": "Bob",
//       "role": "Manager"
//     }
//   ]
// }

count = [[result SizeOfArray: @"value"] intValue];
i = 0;
while (i < count) {
    result.I = [NSNumber numberWithInt: i];
    NSLog(@"%@%@",@"name: ",[result StringOf: @"value[i].name"]);
    NSLog(@"%@%@",@"role: ",[result StringOf: @"value[i].role"]);
    NSLog(@"%@%d",@"id: ",[[result IntOf: @"value[i].id"] intValue]);
    NSLog(@"%@",@"");
    i = i + 1;
}